Abstract

Optical imaging is emerging as a non-invasive and non-ionizing method for breast cancer diagnosis. A hand-held optical imager has been developed with coregistration facilities towards flexible imaging of different tissue volumes and curvatures in near real-time. Herein, fluorescence-enhanced optical imaging experiments are performed to demonstrate deeper target detection under perfect and imperfect (100:1) uptake conditions in (liquid) tissue phantoms and in vitro. Upon summation of multiple scans (fluorescence intensity images), fluorescent targets are detected at greater depths than from single scan alone.

Figures (6)

Three-step coregistered imaging process. In Step #1, the source and detector locations are tracked in real-time with respect to the phantom. In Step #2, a raw image (of optical measurement) is collected and used to generate a 2D surface contour plot of the corresponding (here fluorescence intensity) data. In Step #3, the positional information is used to accurately coregister the image to the probe’s location on the discretized phantom mesh.

Experimental set-up for phantom studies. (A) A spherical target filled with 1 µM indocyanine green is enclosed within the cubical phantom to represent a tumor. (B) The phantom is composed of a 1% Liposyn solution to mimic the optical properties of human breast tissue.

Coregistered images from single scans (2D contour plots of fluorescence intensity data) at four probe positions for experimental case #12 (a 0.45 cm3 fluorescent target placed 3.0 cm deep, x-dimension in-vitro phantom under T:B = 1:0). In each image, the white dotted line represents the probe position with respect to the phantom and the black open circle represents the true target location.

Summated image of multiple scans shown in Fig. 4 (experimental case #12). The summed image represents summation of 8 single scans, where 2 scans were collected at each of the 4 probe positions shown in Fig. 4. The black open circle represents the true target location.

Tables (1)

Table 1 Summary of experimental studies in which a target was detected in tissue phantoms and in vitro. The cases where the deepest target was detected for phantom or in vitro, and perfect or imperfect uptake are highlighted in red.

Metrics

Table 1

Summary of experimental studies in which a target was detected in tissue phantoms and in vitro. The cases where the deepest target was detected for phantom or in vitro, and perfect or imperfect uptake are highlighted in red.